Apparatus for manufacturing metal parts by deformation



Feb. 23, 1965 R. GAURIAT APPARATUS FOR MANUFACTURING METAL PARTS BYDEFORMATION Filed Sept. 7, 1962 INVBNTOR Roger G'aurmi ATTORNEYS UnitedStates Patent 1 Claim. (01. 80- 24) This invention pertains to themanufacture of metallic parts, particularly blades for turbo-machinessuch as steam and gas turbines and also axial compressors, and isrelated to the improved method for making such blades as disclosed andclaimed in a co-pending application Serial No. 222,132, filed September7, 1962 and assigned to the same assignee as is the instant application.

In accordance with the improved method for making turbine and compressorblades as disclosed in the aforesaid co-pending application, one startswith a metallic bar section of suitable length and passes this barthrough a rolling mill, the rolls of which are constituted by segmentsof a cylinder and wherein one or both ends of these roll segments areprovided with recesses so that only the intermediate, or body section ofthe blade will be produced by the rolling and reduction of anintermediate portion of the metallic bar section. One or both ends ofthe metallic barsection which are to form the foot, or foot and headrespectively of the blade are not rolled because of the end recesses inthe roll segments thus leaving substantially unworked masses of the barat one or both ends respectively. Thereafter, the partly completed bladeis transferred to a press where the fillets between the body and footand head end portions of the blade are finished pressed to the desiredcurvature and dimensions.

In a case where the blade is to have a head as well as a foot portion,it is necessary to provide, between the body of the blade and the endportion of the length of the original bar section which is last to passbetween the roll segments of the rolling mill, a sufficient clearance sothat said end portion will not be damaged by the posterior end of theroll segments during ejection. Such a clearance can lead to a filletzone of connection between that end part, which may be the head or foot,and the reduced body portion that flares too much to be acceptable.

In accordance with the present invention, the roll segments of therolling mill are designed in such manner that there is no longer anyappreciable difference in the fillet zones between the body portion ofthe blade and the head and foot portions thereof. More particularly, atthe posterior end of each roll segment, upper and lower, after thetrailing recess intended for the head or foot of the blade, wherever maybe the case, there is provided a terminal part with a radius larger thanthe greatest radius of the remainder of the roll segment which servesthe function of retaining the metal which tends to stretch as a resultof rolling of the body portion of the blade and, at the end of rotationof the roll segment compresses this metal in order to include the samein the trailing recess. p

This trailing terminal part on the upper and lower roll segments serveconjointly both as a stop retaining the metal and as a punch compressingit. Under its action, the metal is obliged to fill the entire trailingrecess and thereby to line the internal angles which, without thiscompression, might not receive any metal at all.

The invention is illustrated in the accompanying drawings which show onesuitable arrangement for the im- 3,170,343 Patented Feb. 23, 1965 "icethese drawingsz' FIGS; 1-4 is a sequence of views showing the barsection in various positions as it passes through and between the rollsegments;

FIG. 5 is an end view of the roll section illustrating one suitableconfiguration for the trailing parts of the roll segments whichcooperate to establish a stop-punch operation on the trailing end of thebar section; and

7 'FIG. 6 is an end view, similar to FIG. 5 illustrating anothersuitable configuration for the trailing parts of the roll segments. I

With reference now to FIGS. 1-4, the lower and upper cylinders of thereduction rolling mill are illustrated some- What schematically at 1 and2, respectively. The roll segment on cylinder 1 is shown in section at 3and the roll segment on cylinder 2 is shown in section at 4. At theirposterior or trailing end, i.e. the end last to pass between thecylinders, the segments are provided with trailing portions g and h ofgreater radius than the remainder of the roll segment which follow theirrespective trailing recesses a-b-c and d-e-f and which functionconjointly to establish the stop-punch above referred to.

In FIG. 1, the bar section 5 to be formed into the blade is shown as itis about to be engaged by the roll segments 3 and 4 to form the bodyportion of the blade, it being noted that due to the presence ofrecesses r and r at the leading ends of the roll segments, the leadingend portion 5a of the bar section will pass through without anyappreciable working by the roll segments.

FIG. 2 shows the bar section 5 after engagement by the leading rollingsurfaces of the roll segments, the leading end 5a of the bar 5, which isto form a foot or head portion, having already been delimited from theintermediate portion 5b which has just commenced to be rolled andreduced by the roll segments 3 and 4.

In FIG. 3, rolling of the intermediate part 5b of the bar section whichis to form the body part of the blade is half finished. The posteriorterminal edges a and f of roll segments 3 and 4 respectively have justengaged the surface of the bar 5 while producing a certain flare. Atthis moment, the stop-punch elements g and h come into contact with theposterior end 50 of the bar 5. V

In FIG. 4, which shows the bar section 5 at the end of the rollingoperation, it will be seen that due to the stop punch action provided bythe cooperative trailing portions g and h of the roll segments, themetal constituting the trailing end portion 50 of the bar section 5 willhave been pressed into the space abcdef constituted by the junction ofthe posterior recesses of the roll segments 3 and 4. The metal nicelyfills the angles b and e which otherwise would lack metal because of therotation of points a and f.

Moreover, the stop-punch provided by the trailing portions g and h ofthe roll segments are in relief on the segments and the sum of theiroutside radius is greater than the interaxial distance of the segments.Hence, it is necessary to machine them in such a way that theyinterpenetrate so that the rotary movement can continue. For thispurpose, various configurations of the trailing portions g and h can beadopted. FIG. 5 shows one suitable embodiment, as viewed when looking inthe direction of the arrow of FIG. 4, the trailing portion on rollsegment 3 being constituted by two parallel spaced projecting portions gand g which overlap and engage the side faces of a centrally locatedtrailing portion h on roll segment 4 which slides between the projectingportions 51 and 82- FIG. 6 shows a slightly different embodiment whereinthe trailing portion on roll segment 3 is constituted by an upwardlyprojecting portion g, which overlaps a similar but complementaryconfigured downwardly projecting portion it on roll segment 4, the innerfaces of these two projecting portions being in sliding contact witheach other.

After the bar section 5' has been rolled in the rolling mill section inaccordance with the present invention to produce the body portion of theblade, it is then transferred to the press unit as more fully describedin the aforesaid co-pending application Serial No; 222,132 for furtherprocessing to finish the fillet portions between the body and the headand foot portions.

In conclusion, while the invention has been described in its relation tothe production of turbine and like blades, the principles thereof-areequally applicable to any other metallic part having a profiled centralor body portion included between two terminal enlargements.

I claim:

In a reduction mill apparatus-for producing a profiled central bodyportion included between two terminal enlargements on a metallic part,comprising upper and lower roll segments adapted to engage and roll saidmetallic part, said roll segments each being provided with leading andtrailing recesses in the rolling surfaces thereof adapted to clear theleading and trailing ends of the metallic part and thus result in thereduction of only the central body portion to the desired profile, andthe trailing end of each of said roll segments being provided with aterminal part having a radius greater than the greatest radius of theremainder of the roll segment, said terminal parts acting conjointly toretain the metal at the trailing terminal enlargement which tends tostretch during the rolling and to compress it into the trailing recessedportions of said roll segments.

References Cited by the Examiner UNITED STATES PATENTS CHARLES W.LANHAM, Primary Examiner.

